A plasma display panel (hereinafter simply referred to as a “PDP” or a “panel”) as a kind of display panel is formed of a front panel and a rear panel confronting each other, and these panels are sealed with a sealing member at their peripheries. A discharge space is formed between the front and rear panels, and discharge gases such as neon and xenon are filled in the discharge space.
The front panel comprises the following elements:                plural display-electrode pairs including scan electrodes and sustain electrodes both formed in stripe patterns on a surface of a glass substrate; and        a dielectric layer and a protective layer both covering the display electrode pairs.Each one of the display electrode pairs is formed of a transparent electrode and a metallic auxiliary electrode formed on the transparent electrode.        
The rear panel comprises the following elements:                plural address electrodes formed on another glass substrate in stripe patterns along the direction intersecting at right angles with the display electrode pairs;        a base dielectric layer covering these address electrodes;        barrier-ribs formed in stripe patterns and partitioning the discharge space along respective address electrodes; and        a phosphor layer painted in red, green, and blue sequentially at respective grooves between the barrier-ribs.        
The display electrode pairs intersect with the address electrodes at right angles, and the intersections form discharge cells which are arranged in matrix patterns. A set of three discharge cells colored in red, green, and blue respectively lined along the display electrode pair forms a pixel for color display. The PDP shows a color video through the following mechanism: a given voltage is applied between the scan electrode and address electrode, and between the scan electrode and the sustain electrode sequentially, thereby generating gas-discharge, which produces ultraviolet ray. The ultraviolet ray energizes the phosphor layer for light emission, so that a color video can be displayed.
The front and rear panels are manufactured in this way: structural elements such as the display electrode pairs, and the dielectric layer are formed on the front glass substrate in a given shape and pattern. Structural elements such as the address electrodes, base dielectric layer, barrier-ribs, and phosphor layer are formed on the rear glass substrate in a given shape and pattern. The respective materials are applied on each one of the glass substrates, and undergo patterning by a photolithography method or a sand blast method as required, then baked.
The predetermined materials as discussed above are applied on the respective glass substrates for forming a material layer, then the layer is baked to be hardened, thereby forming the respective structural elements on the glass substrate. In the baking and hardening step, the glass substrate is placed on a supporting bed and put into an baking furnace together with the bed for baking the material layer. In the baking furnace, a temperature as high as 500-600° C. is kept, and therefore, the bed is made of ceramic material such as neoceram N-0 or N-11 (names of products made by Nippon Electric Glass Co., Ltd.) because of their high heat resistance, and the glass substrate employs highly distortion-resistant glass. An instance of preventing a misalignment between the supporting bed and the substrate during the forgoing baking and hardening step is disclosed in the Unexamined Japanese Patent Publication No. 2003-51251.
However, plural small scratches are produced on the glass substrate surface, contacting the supporting bed due to a difference in thermal expansion coefficient between the supporting bed and the substrate during the baking and hardening step discussed above. To be more specific, heat resistant material having a thermal expansion coefficient of −0.4×10−6/° C. is used for the supporting bed, and highly distortion-resistant glass having a thermal expansion coefficient of 8.3×10−6/° C. is used as the glass substrate. Since the bed and the substrate have such a difference between their thermal expansion coefficients, the surface of the glass substrate is rubbed with the supporting bed, thereby being scratched. In the case of the rear panel, these scratches are less significant; however, in the case of the front panel on which a video is displayed, the scratches degrade the display quality and reduce the manufacturing yield.